Machine for welding tubes.



G. OSTEBMANNI MACHINE FOR WELDING TUBES.

APPLICATION FILED 00114, 1912.

;-,% 6 1O wanted @ct. 21, 1913.

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W l i 771865. l77vera'?'or G'WMMW (gmqfav OSfer'mQ Afforrmys G.GSTERMANN. MACHINE POE WELDING TUBES. APPLIUATIGN FILED 001214, 1912.LQT/fifiQL-L Patented m. 21, m3.

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Aiiorngg GUSTAV) oszrna uann, or. COLOGNE-RIEHL, GERMANY.-

macnmn roe WELDING TUBES.

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Specification of Letters Batent.

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' Application filedflctoberlgl, 1&12; Serial No. 725,662.

I specification.

The present invention relates to an improved machine for welding tubesof the kind, in which strips ofsheet metal are bent, after beinpreviously heated, into the shape of a tube caving a narrow slitopenwhere upon this slit is welded together by means of a blowpipe flame. 5

The present invention essentially consists in an arrangement bymeans'of'which itis possible to make the said welded sea-m of either thesame thickness or of a greater thickness than the material of the tube,and of a regular shape and direction.

The machine will allow of continuously welding tubes of any length, thefinished tubes being at the sam'etime cleaned, roundedand straightened,all at a very small consumption of fuel and within a small space.

The characteristic feature of the present invention lies in the seriesin which the several operations or-tools are employed. According to theresent invent-ion the-tube bent into shape 1s preliminarily heated in amuflle furnace to a certain, not too high temperature and then passesthrough an arrangement which will straighten and keep the slit open.Then follows a blowpipe burner which heats the edgesof the slittofusingtemperature and immediately behind the burner are the weldingrollers, which close theslit and weld the edges ofthe same together.'Ilhereuponthe-tube asses through wire brushes and forming rolFers andlastly through a set of straightening. rollers.

In the accompanying drawin the machine is exemplified in Figure 1 inside elevation,

in Fig. 2 ina top plan view;.Figs. 3and 4 show details of the feedrollers and the welding rollers.

The tube 1' formed of a strip of sheet metal bent into the shape of 'atube first passes in the direction of the arrow between the airs ofrollers a.a and-"Mb respective y, of which the rollers a and b aredriven by means of worm and wormwheels from the shaft 0. dividedvertically to their axis into two sym- The rollers a and 'b are metricalhalves (see Fig. 3), these halves being held together by means of screwsand the like, and between them is arranged a thin disk d sharpened atits edge, the said sharpened edge engaging in the slit of the tube 1- tobe welded andthereby keeping the said slit in the proper position. Thetube then passes the mufile furnace e, which may be heated by anysuitable fuel and is there heated to a slight red heat. Behind thefurnace the tube passes beneath a roller f, beveled at its periphery andadjustable in a vertical direction by means of the handwheel g; thisroller f engages with its beveled: edge in the slit of: the tube 7' andthere by also keeps the latter in the proper position, at the same timewidening the said slit slightly. In place of the roller f also astationary nose, beveled at its lower side may be employed to the sameeffect. The tube then passes beneath the welding burner h, which isarranged on a pillar and is adjustable in three directions; here theedges of the slit are fused. Immediately behind the welding burner thetube is passed between the horizontal rollers 2' and 2' which are shownseparately in Fig. 4. These rollers will compress the tube in such amanner, that the fused edges will be pressed against eachotherandthereby the welding of the seam willbe-produced. Between the rollerornose f and the rollers 21 and 2' the slit will assume a.wedgelikeshape at the apex of Whichthe welding will be easily effected.By raisin-g or lowerin the roller f the width of the slit at the pointwhere the welding burner acts on it may be regulated in an accuratemanner, what is very important for obtaining a good welding. The roller2' is driven from the shaft 0 by means of a gearing and the Wornilc, theshaft of roller 2' being fitted in a. slide which may be ad.- justedtransversely to the direction of'tlie axis .of the tube by means of ahandwheel Z (see Fig. 3), so that the distance between the rollers z'and i and therewith the welding pressure exerted on the tube may bevaried. 1

Behind the welding rollers 2' and 71 the tube passes the revolving wirebrush m, which will remove all oxids or scale ad hering to thewelded-seam. The tube then asses between the pair of rollers n and 11.in Which it will be properly rounded, as it will frequently assume asomewhat oval shape by the welding process. The rgller n is again drivenby me-ans: of'worm and wormwheel from the shaft 0, whilefthe rollern'runs loose onits shaft 0, but somewhat eccentricallyto"'the'-"-bearing of said shaft, so that by, turning this. shaft bymeans of lever 77 and handwlie'el gfihe distance between the rollers 11.and h 'may be accurately adjusted. Lastly the tube still passes thethree rollers s, 8 s of which the upper one s is adjustable in a similarmanner as the roller 10 by means of the handwheel t. This last set ofrollers will straighten the welded tube. The machine is driven by meansof the shaft u which drives by a sprocket wheel a and chain the wirebrush m, and transmits its rotation to the shaft 0 by a face disk at andthe friction rollers y. The friction roller y can be displaced on theshaft 0 by means of the handwheel 2, so that the speed of the wholemachine may be controlled by such means.

By employing-a welding burner or blow pipe of the known kind for fusingthe slit which has been straightened and opened by the roller or nose f,together with the welding rollers 2' acting immediately behind saidburner, the heating is reduced to a comparatively short piece of theslit, and only this short piece heated to welding heat will be welded ata time. By the cooperation of theseparts the seam is prevented'fromwelding together before reaching the welding rollers 71; the slit willremain open until it enters between the welding rollers and will beclosed only on the tube passing between these rollers. A furtherconsiderable advantage is obtained by the provision of the straighteningrollers s. Bythe coaction of the three rollers the still plastic tube isstraightened and the heat from the welding operation still contained inthe tube is utilized both for rounding the tube and for straightening itin a very simple manner. These rollers also aflord the advantage, thatthe tube may be given, while still in the welding machine, also anyother shape except a straight shape, so that according as the rollers 8,8 s are adjusted relatively to each other, the tube may leave themachine for instance in spirals or bundles and be bentin any givendirection for its further use. Lastly the simple method of driving thevarious parts of the machine and of controlling them represents afurther advantage of the machine.

Having now described my invention what I claim and desire to secure byLetters Patent of the United States is:

1. In a tube welding machine, the combination of a muflie furnace, meansfor widening the slit in the tube to be treated, a

blowpipe burner for heating the edges of the slit to a fusing heat, andwelding rollers for pressing and welding together the edges of the slit.

2. In a tube welding machine, the combination of a muffle furnace, meansin front of said furnace for straightening the slit in the tube to bewelded, means in the rear of said furnace for widening said slit, ablowpipe burner for heating the edges thereof to afusing heat, andWelding rollers for pressing and welding the edges of the slit together.

3. In a tube welding machine, the combination of a muffle furnace, meansin the front of said furnace for straightening the slit in the tube tobe welded, a beveled nose in the rear of said furnace for engaging saidslit, a blowpipeburner for heating the edges of said slit to a fusingheat, and weld- I ing rollers for pressing and welding the edges -of theslit together.

4. In a tube welding machine, the combination of a muflie furnace, meansin the front of said furnace for straightening the slit in the tube tobe welded, a beveled nose in the rear of said furnace for engaging saidslit, said nose being rotatable and in the form of a roller having abeveled edge, a blowpipe burner for heating the edges of said slit to afusing heat, and welding rollers for pressing and welding the edges ofthe slit together.

5. In a tube welding machine, the combination of a: mufiie furnace,means in the front of said furnace for straightening the slit in thetube to be welded, a beveled nose in the rear of said furnace forengaging said slit, a blowpipe burner for heating the edges of said slitto a fusing heat, and welding rollers for pressing and welding the edgesof the slit together, said beveled nose being adjustable.

6. In a tube welding machine, the combination' of a muffle furnace;means for widening the slit in the tube to be treated, a blowpipe burnerfor heating the edges of the slit to a fusing heat, rollers next in rearof said burner and standing in a plane to press and weld together theedges of the slit, and other rollers standing in rear of the first-'named rollers and standing in a plane for compressing the tube atrightangles to the first-named plane.

In testimony whereof I have hereunto set my hand in presence of twosubscribing

